README

* Citation to the publication associated with the datasets and code 
Title: Positional intra-clutch variation in egg shape associated with maternal guarding in a shield bug
Journal: The American Naturalist


* Author names, contact details
Authors: Hirotaka Masamoto, Takahiro Hosokawa, Shin-ichi Kudo
Corresponding author: Hirotaka Masamoto
Contact details: Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan (hirotakamasamoto1216@gmail.com)

* A brief summary of what the study is about
We investigated whether egg shape varies with position within a clutch in the sub-social shield bug S. esakii. Our analysis revealed that centrally located eggs were more elongated than peripheral ones, while maintaining comparable width. This positional variation in egg shape may allow females to compactly pack the clutch within the limited protective space beneath their bodies, with minimizing the number of vulnerable peripheral eggs, while allocating more resources to central eggs. 

* Identify who is responsible for collecting data and writing code
Hirotaka Masamoto, corresponding author

* Data and code files

There is one data file: “EggMeasurementsData.csv”. It contains 640 rows (excluding the header row), each representing an individual egg. The dataset includes 7 columns, described as follows.
ClutchID: A unique identification number assigned to each clutch (i.e., female).
EggPosition: The specific position within the clutch where the eggs were sampled (center/periphery).
EggID: A unique identification number assigned to the 10 eggs sampled from a specific position (center/periphery) within a clutch (1, 2, 3, … 10).
EggLongDiameter: The long diameter of the egg, measured in millimeters (mm).
EggShortDiameter: The short diameter of the egg, measured in millimeters (mm).
EggVolume: The volume of the egg, estimated as an ellipsoid.
ProthoraxWidth: The prothorax width of the female, measured in millimeters (mm).

There is one code file: “EggShapeAnalysis.R”. It contains the code for generating the figures and performing statistical analyses presented in this paper. We ran the code using R version 4.4.2 and lme4 package version 1.1.36.